Hamilton Khaki Field Mechanical Power ReservevsLongines LONGINES MASTER COLLECTION

The Hamilton Khaki Field Mechanical Power Reserve is noted for its 40mm sandblasted case, filling a size gap in the Khaki Field line. It features a new H-23 hand-wound movement with an 80-hour power reserve and a functional power reserve indicator at 9 o'clock. The case is 11.95mm thick, which is described as noticeably thicker than other Khaki Field models, and its proportions differ from classic manual-wind versions. The movement includes a slipping spring to resynchronize the power reserve indicator after shocks. Overall, reviewers appreciate the addition of the power reserve complication to the hand-wound model, though one reviewer noted a preference for a contrasting color on the indicator.

Owners widely praise the Longines Master Collection for its attractive designs, heritage feel, and value, with specific models highlighted for their legibility and manageable sizes. One owner finds the 40mm moonphase chronograph complete calendar mesmerizing and versatile at around $1700, while another appreciates the 38mm World Timer's looks and blue hands. A drawback noted across different models is limited water resistance, with one owner selling their watch due to this, and the World Timer disc requiring manual adjustment for daylight saving time in some areas. On balance, owners rate the Longines Master Collection highly for its aesthetic appeal and value proposition, despite some limitations in water resistance and functionality.